Category: Sizing

Nutanix Hybrid Selection Guide

In earlier post I went through some Nutanix spec sheet issues and while describing some disk size related issues, I made SSD/HDD capacity ratio calculations with Nutanix Hybrid (SSD+HDD) setups. I used only couple of SSD+HDD setups and Nutanix NX platforms as an example.

  • Why not go through possible SSD/HDD ratio ranges for more NX platforms?
  • Find the floor and the ceiling for SSD/HDD ratios?
  • It might be useful in selecting NX Hybrid setup for workloads with certain requirements for SSD/HDD ratio?

Continue reading “Nutanix Hybrid Selection Guide” →

Death of 10k SAS drive?

There is a famous quote by Mark Twain “The reports of my death have been greatly exaggerated”, and despite claims made by All Flash disk array manufactures, this quote still holds true for 10 k SAS drives when comparing only cost per gigabyte. SSD drives have been and are still more costly per gigabyte than their spinning ancestors 10k SAS drives.

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Economic impact: Scale Out vs Scale Up, Part 2

This is the second part of this series, the first part can be found from here.

  • Starting point is very similar as with Scale Up sizing exercise
  • Collect some performance data from existing system in order to estimate growth rate
  • Select over how many years solutions should be amortized
    • Typically three to five years
    • With Scale Out you don’t initially size / buy solution for the whole three to five years, but it is good to know your upper limit, especially if there are limits in Scale Out cluster size
  • Based on collected data, plot required scaling over years
  • You might also want to plot different scenarios at different growth rates

Continue reading “Economic impact: Scale Out vs Scale Up, Part 2” →

Economic impact: Scale-Out vs Scale-Up, Part 1

In this two part series I will study different ways to scale resources in data centers and how chosen model impacts costs.

In Virtualized Data Centers performance is one of the most common factors limiting scaling.

Compute layer has a Scale Out model for performance:

  • If you need more compute power just add servers to a shared resource pool
  • Balance load by live migrating VMs to new servers
  • Keep using one management point
  • No additional silos
  • Nearly linear scaling
  • Problem solved

Continue reading “Economic impact: Scale-Out vs Scale-Up, Part 1” →